Fan driving mechanism



March 8, 1932. E oCRAY 1,848,260

FAN DRIVING MECHANI SM Filed June 8, 1927 2 Sheets-Sheet 1 Lflifis a W MWE Meimh 8, 1932. H. E M cRAY FAN DRIVING MECHANISM 2 Sheets-Sheet Filed June 8, 1927 RAM Patented Mar. 8, 1932 Eamon]; n'l menu, or warnaro BANY, or warnnnoo.

0, rowA, Assrenon To .ioniv DEERE IOWA, a conroimrroiv oniown TRACTOR com- FAN nnrvrneivrncnnmslvi I Application filed June 8,

The present invention relates to driving mechanisms for the fans of internal combustion engine cooling systems having. particular reference, in certain details, toa fan driving mechanism for'farm tractors of the generaldesign illustrated in the copending application of Louis W. lVitry, 682,401, filed December 2 1, 1923.

The objects of the invention are to provide an improvedconstruction of fan driving mechanism characterized by a friction slippage action for absorbing inertia shock between the fan and its driving shaftthis being particularly desirable where the fan shaft has a positive gear drive from the motor, as in the present construction and to provide an improved construction of adjust- I able bearingfor the fan shaft so as to enable the latter to be adjusted radially in the as 2p sembly of the driving mechanism for obtain- Serial N 111g proper mesh of the gears which drive the fan shaft. 7 I

Referring to the accompanying drawings illustratingthe preferred embodiment of my 5 invention:

Figure 1 is a fragmentaryside view, partlyin section and partly in elevation, of the front end of afarm tractor in which the invention is embodied. e

Fig. 2 is a fragmentary sectional view taken longitudinally of the fan'shaft-on the plane of the. line2"-2 ofFigure 1. Fig. 3 is a fragmentary sectional view taken on the'plane' of the line33 of Fig. 4:, illustrating the adjustable bearing support for therear end of the fan shaft, and

Fig. 4 is a transverse sectional View of this adjustable bearing, taken on the plane of the line 4tof Fig.3 a V Referring to Figure 1, illustrating the front portion of a tractor of the type to which, my invention has particular application, it will be seen that the internal .combustion motor 6 is of the horizontal type, having the connecting rods? from its pistons 8 extending rearwardly ,into a crank case 9 for connection with a transversely extending crank shaft 11. Supported Ion the front of the tractor is the usual cooling radiator 12, having connectionv with the cooling 1927. Serial No., 197,312. g p jackets 13 of the cylinder block 14. Extenda 111g rearwardly' from the upper portion or the radiator is a fuel tank 15, the interior of which is partitioned into separate compart-,

ments for holding gasoline and kerosene. Bolted to the upper side of the cylinder block 14 is a hollow standard 16 which serves to support'the front end of the fuel tank 15, and which also serves as a duct for conveying the heated water from the cylinder jackets 13 up to the upper portion of the radiator 12. i

The cooling fan 17 is disposed directly in rear of the radiator 12 for drawing, air therethrough, and is mounted. on a fan shaft 18 supported above the cylinder=block ltand extending rearwardlyinto a housing 19' which is secured to the top of the crank case 9. Referring to Fig. 2, this casing 19 encloses a magneto and'governor drive shaft 21 which has bearing support in ball bearings 22 carried in ball race housings 23 secured in-the end walls of the casing. The bottom of said casing is open and communicates with an opening in the top of the crank case 9. Mounted on which projects down through this opening and meshes with an idler gear 25 suitably journal'ed in the crank case.-

is driven from a gear25 on the crank shaft 11,

whereby power is transmitted from the crank shaft to the shaft 21. I

' As before remarked, the shaft 21 "serves to drive the governor. mechanism and the magneto of themotor, but inasmuch as these devices constitute no part of the present invention I shall only refer in brief to their operating connection to this. shaft. The

governor mechanism compr ses .a plurality of counterweighted bell cranks 27 pivotally mounted on the side of the gear 24 and arranged to impart thrusting movement to a sleeve 28 which is slidably mounted on the shaft-.21. The endwise movement of such sleeve is transmitted through a thrust bearing 29 to a bellcrank-lever 31, whichv operates through a shaft 32 and through other connections not shown to regulate the position of a throttle in the intake manifold of the motor. The magneto 33 is connected to a coupling the shaft 21 is a spur gear 24.

Such idler gear through the center of v fan shaft." W

' The fan 17 is mounted on said shaft directly member 34 which is keyed to one end of the shaft 21 I The fan shaft 18 is positively driven from the governor and magneto drive shaft 21 through a bevel pinion 35, keyed to the fan shaft, which meshes with a bevel gear 36 keyed to the shaft 21. The gear end of the fan shaft 18 has bearing support'in the front wall of the casing 19, in a construction of adjustable'bearing which I shallhereinafter describe. The fan shaft extends forwardly the hollow standard 16, the latter being provided with a sleeve 37 that extends fore and aft therethrough and for a short distance forwardly therefrom, said sleeve being preferably formed integral with the standard to prevent the leakage-of water from the duct within the standard. At its "forward end "this sleeve is formed with a bearing housing 38 in which is'mounted a ball bearing 39 supporting the front end of the beyond the bearing housing 38, and comprises thensual fan blades 41 which are riveted to arms 42radiatingfrom a central hub portion 43; The hub comprises a radially extending web'portion 44 whichha's frictional en gement between two driving collars 45 and tti mounted on the fanshaft 18. The hub ortions of these collars are non-rotatably secured to tlie'fanshaft by a driving key 47. A nut 48 screws overthe reduced threaded end 49*0f the drive shaft andserves as a stop for limiting forward movementof. the collar Extending outwardly from the inner ends of these collars are radially extending plate portions 51'and 52 respectively, which engageagainst opposite sides of the fan hub 7 portion 44. The inner collar 45 is slidable longitudinally along the key 47, and acoinpression spring 53 is confined between the rear side of its plate portion 51 and a rearwardly spaced stop'collar 54;""Thepressure of-such spring forces the opposing surfaces of the plate portions 5152 and of the hub portion 44 in firm frictional driving engagement. Interposed between these contacting faces are disks 55 of suitable frictional material for increasing the frictional engagement between said surfaces. Ife'desired, these disks may be riveted to the plate portions 51-52, or to the intermediate hub portion44, but I consider it more desirable to leave these disks free to rotate relative to each of the aforesaid members so as to increase the number of slippage surfaces: I j I I "Extending laterally from the outer part of the intermediatewe'b portion '44 are flanges 56-'56,th'ef inner sides of which are'fo'rmed to' have a'bearingfit on" the peripheries ofthe plate portions "51 52; These-flanges thus constitute radial bearing surfaces for-the fan hub, the central'part ofthe intermediateweb turin g discrepancies portion 44 having no contact with the shaft 1 It will be evident that the foregoing construction provides a friction slippage connection between the fan and its characterized by an extensive area of frictional slippage surfaces. The purpose of this slippage connection is to safeguard the fan and its driving mechanism against inertia shocks which occur when the engine starts and when its speed is accelerated quickly, such inertia shocks being injurious in the case of a positively driven fan shaft-such as has beendescribedeunless provision be made for absorbing these shocks. The spring 53 maintains a definitefrictional pressure between the frictionlportions 5152 of the collars and the web ortion 44 of the fan hub which will permit s 'ppage between the shaft and the fan] upon starting and sudden acceleration,

driving shaft,

butwhich will hold the fan at the same rotat brought up to speed. By employing two collars keyed to the shaft, with theffrictional portion of thefan hub interposed between such collars, in the manner shown, I have doubled the effective area of frictional surface, and have thus increased the wear. resisting' qualtities of the slippage connection. Moreover, the fan in its operation of drawing airthrough the radiator has a forwardly, acting end thrust set up therein, and this forceisalso utilized to increase the friction of the slippage connection, such followin from the 'fact that, this end thrust will ten tolfiorce the web portion 44 of the fan forwardly against the collar plate 52 with a pressure proportional to the speed of. IQtation of the fan'. v I

The housing 38 which contains the ball bearing 39 is closed at it, front end by a 'removable cap 58 in which is mounted a lubria t. reta n ng pac ing. 59.- h t er ears on a sleeve 61 which extends betweentbe thrust collar 54 and the inner race of the ball bearing39f, whereby thethrust of thespring 54 is carried by'jsuchbearing. A separate lubricant retaining packing (52 may be recessed in the inner portion of the housing in rear of the, bearing 39. Any suitable oil cup or nipple63 may be provided for; supplying lubricant to 1 the ,bearlng.

Because of unavoidable variations in the castings, in the machining thereofand, in the assembl of the pa rts,-it frequently happens'that t 1e rear end of the fan shaft 18 is notproperly alined'forthe most eflicient meshingof the bevel pinion 35 withthe bevel gear 36. To compensate for these manufac- I have provided ashiftablebearing'lnember for the rearend ofvthe tween the'two bevel gears.'- As best shown in fan shaft, by which this end. otthe shaft and I Figs. 3 and e, such bearing member comprises a housing portion 64 in which is confined a lubricant packing 65 and aball bearing 66. The outer race 67 of said bearing is seated in the bearing member 64 and the inner race 68 thereof is mounted on the shaft be-r. The bearingmember comprises a ribbed flange 72 adapted to abut against the face- 18. The bearing member is adapted to be secured to the front face of a boss 69 which projects from the front wall of the casing .19,this boss being provided with a plurality of threaded holes 71, preferably three in numof this supporting member or boss 69. Formed-in the'flanged portion 72 are three holes 78 for receiving cap screws 74 adapted to screw into the tapped holes 71. The holes 7 3 are substantially larger than the shank portions of the cap screws 74, as shown, in

, order that the bearing member can be shifted radially in any desired direction for moving ment. The ball bearings 39 and 66 at the opposite ends of the fan shaft are inherently selfealigning to a limited degree, which enables these bearings to accommodate easily.

the very slight adjustments in shaft alignment necessary to secure proper mesh of the bevel gears,

What I claim as my invention and desire to I secure by Letters Patent, is-

1. A driving mechanism for a radiator cooling fan, said mechanism comprising a shaft for driving the fan, a pair of collars keyed to said shaft for rotation therewith,

= each of said collars comprising a radially extending plate portion, the rear collar being slidable longitudinally of the shaft and the front collar being fixed from longitudinal movement, a hub for said fan comprising a portion having frictional engagement between said collars, spring means for holding the plate portions of said collars and the fric tional portion of said. hub in frictional driving engagement, and means providing a bearing surface on said hub and having bearing engagement with the said plate portions.

2. A driving mechanism for a radiator cooling fan, said mechanismcomprising a fan shaft having positive driving connection with a motor, apair of collars keyed to said shaft to rotate therewith, the rear collar being slidable longitudinally of said shaft and the front collar being fixed from longitudinal 1 portion, the front collar periphery of one of radially extending plate portion, a hub for said fan, comprising a radially extending web portion interposed between the plate portions of said collars, a spring urging against the slidable collar for establishing frictional driving engagement between the opposing faces of said plate portions and said web portion, and laterally extending flanges on said I extending plate portions.

'3. A" driving mechanism for a, radiator cooling fan, said mechanism comprising a fan shaft'having positive driving connection with a motor, a pair of collars keyed to said shaft to rotate therewith, each of said 001- hub having radial bearing engagement on the I periphery of said radially lars comprising a radially extending plate being fixed to the shaft andthe rear collar being slidable along said shaft, a hub for said fan comprising a radially extending web between the plate portion of said collars,

portion interposed loose friction discs interposed between said web portion and theplate portions of said collars, openingthrough the central portion of said frictiondiscs, a spring urging against the slidable collar for establishing frictional driving engagement betweensaid shaft and said fan, and laterally extending flanges on a said hub having radial bearing engagement on the periphery'of said radially extending I plate portions, for retaining said friction discs in position.

- kA driving mechanism for a radiator cooling fan, said mechanism comprising a fan shaft having positive driving connection with a motor, a'pair of collars on said shaft, a key splined in said shaft and passing through both of said collars for securing them for rotation therewith, the front collar being fixed from longitudinal movement relative to the shaft, andthe rear collar being movable along the shaft, each orsaid collars comprising a radiallyextending plate portion, a hub for said fan, comprising a radially extending web portion interposed between the portions of said collars, loose friction plate discs nterposed between said web portion and said plate portions, openings through the center of said friction discs, a spring urging against the "slidable collar for establishing frictional drivingengagement between the opposing faces of said plate portions and said web portions through the medium of said friction discs, and laterally extending flanges on said hub having radial bearing engagement on the peripheries of said radially extending plate portions for maintaining said friction discs in position.

HAROLD E. MoGRAY.

movement, each of said collars comprising a I 

